Altered oligomerization properties of N316 mutants of Escherichia coli TyrR.
The transcriptional regulator TyrR is known to undergo a dimer-to-hexamer conformational change in response to aromatic amino acids, through which it controls gene expression. In this study, we identified N316D as the second-site suppressor of Escherichia coli TyrR(E274Q), a mutant protein deficient in hexamer formation. N316 variants exhibited altered in vivo regulatory properties, and the most drastic changes were observed for TyrR(N316D) and TyrR(N316R) mutants. Gel filtration analyses revealed that the ligand-mediated oligomer formation was enhanced and diminished for TyrR(N316D) and TyrR(N316R), respectively, compared with the wild-type TyrR. ADP was substituted for ATP in the oligomer formation of TyrR(N316D).
Koyanagi
Takashi
T
Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Katayama
Takane
T
Suzuki
Hideyuki
H
Kumagai
Hidehiko
H
D019943:Amino Acid Substitution; D024322:Amino Acids, Aromatic / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D004885:Erwinia / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010957:Plasmids; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014169:Transformation, Bacterial
D024322:Amino Acids, Aromatic; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C069256:TyrR protein, E coli